Numerical simulation of tropical-cyclone circulation using Arakawa-Schubert cumulus parametrization

Tropical cyclone is simulated from a weak balanced vortex in a numerical model using Arakawa-Schubert cumulus parametrization scheme. A six-level axisymmetric primitive equation model incorporating the cumulus effects is designed for this study. The model consists of four layers in the free atmosphere and one layer for a mixed layer. Three cloud types with tops at 12 km, 8 km and 4 km are possible to form in this model. The results of this numerical experiment clearly indicate the development of a tropical cyclone and the model-derived circulation and structure of the cyclone agree with the observed features. The intensification of the cyclone, the development of radial-vertical circulation and the formation of the eye are well simulated in this experiment. It may be inferred that this parametrization scheme realistically produces tropical-cyclone circulation and will be useful in studies of tropical systems